The construction of a building or dwelling is regulated by a set of standards, referred to collectively when contemplating construction, materials and the like as the building code. The building code is constantly evolving, and is intended to establish a minimum requirement for material dimensions and structural requirements with the objective of providing safe, comfortable and healthy environments.
Energy efficiency has received significant attention in the evolution of the building code, with a view to increasing energy efficiency or, at least, reducing energy consumption thereby to, in consequence, reduce the levels of CO2 in the atmosphere and the costs of operating a building. Newer buildings have been increasingly energy efficient, due to being increasingly insulated. However, with the increases in energy efficiency due to insulation, it has also been recognized that careful attention must be paid to ensuring proper ventilation within the building envelope to avoid condensation.
An area of particular focus for ventilation is the roof space. In roof space, hot moist air from within the building is subject to cooler ambient temperatures, leading to excessive condensation. Such condensation can lead to undesirable deterioration of the building materials. To avoid this, the building code in many jurisdictions mandates ventilation of the roof space to inhibit such condensation.
One scheme for ensuring adequate ventilation involves providing the building with an overhanging soffit running around the periphery of the building's roof, there being portions or the soffit that are perforated or that otherwise permit fluid flow along with one or more ridge or gable vents at elevated locations to promote continuous air circulation in the roof space. The soffit is an integral part of the building structure and is typically incorporated into the design of the roof trusses and/or of rafters. In particular, the roof extends outward from the wall a sufficient distance to provide the ventilation area through the soffit required by the building code after the wall cladding and fascia has been applied.
With the ever-present desire to maximize profits by keeping material to a minimum, the overhang of the soffit is often the minimum allowed by the building code at the time the house was built. In such arrangements, the entire soffit may be perforated to meet the ventilation requirements of the building code.
As for insulation, with new buildings, insulation can be integrated into walls during construction to ensure the buildings comply with the latest insulation requirements in the building code. However, for existing buildings other approaches are required to ensure the buildings better approach the insulation standards of the latest building code. For example, one approach is to add insulation to the exterior wall structure of an existing building. In particular, one may add sheet insulation to the exterior wall structure, using rectangular panels or sheets made of several inches of expanded polystyrene (EPS) such as Styrofoam™ available from Dow Chemical Corporation. After such insulating panels have been installed, a variety of finishes can be used to clad the exterior walls.
Adding EPS panels to the exterior of a building involves arranging the panels to abut the overhang. However, this results in several inches of the perforated soffit, corresponding to the several-inches thickness of the panels and any further cladding applied thereto, being blocked. This accordingly reduces free flow of air into and out of the building. As such, while the insulation has been improved, this consequent reduction in air flow can cause the building code to be contravened for failure to maintain adequate ventilation. Furthermore, it is generally not practical or cost effective to entirely restructure soffits to compensate for the blockages using existing techniques.
It is therefore an object of the present invention to obviate or mitigate the above disadvantages.